Ultimately, Eveline stays in Dublin because of the call of duty that she is forced to heed, thanks to the epiphany she experiences in the final section of the story. This call of duty is something that completely overpowers her. Let us remember that Eveline is described as being "like a helpless animal" at the end of the story, which clearly emphasises her inability to change any aspect of her destiny. Eveline's inability to move and go onto the boat with Frank is indicative of the larger paralysis that seizes control of her life. She cannot free herself from the bar she clutches onto, just as she is unable to free herself from the miserable fate that awaits her as a drudge to her father, who abuses her, and the two children she is responsible for.
Eveline's decision to stay therefore is an act of surrender to the duty that is represented in the promise that she made to her mother and the duty that is implicitly refered to in the promises to Blessed Margaret Mary Alacoque, which significantly hang upon the wall where Eveline is first presented to us. Ultimately, Eveline is presented as a figure who is profoundly incapable of starting afresh, in spite of her desire to do so, and who must surrender to the overwhelming call of duty on her life. Her desire to leave is swamped by the fear and panic of abandoning her duty and god as is shown at the end when she equates leaving with Frank with drowning:
All the seas of the world tumbled about her heart. He was drawing her into them: he would drown her. She gripped with both hands at the iron railing... No! No! No! It was impossible. Her hands clutched the iron in frenzy. Amid the seas she sent a cry of anguish.
Eveline's decision to stay is therefore not a result of a wise consideration of factors. It is also not a result of lack of time to think. It is a visceral, gut reaction that acknowledges the surpassing power of duty on her life and which she finds it impossible to ignore. Her description as a "helpless animal" at the end clearly indicates that her "decision" to stay was not actually a "decision" for her to make at all, rather it was an overwhelming force to which she had no choice but to passively acquiesce.